Context:
Chapter 40 begins the second portion of the Book of Isaiah (3 parts of Isaiah, 1-39, 40-55, 56-66); its common theme is salvation and future blessing of God’s people.
The hearers knew that they were to be in exile for 70 years!
Words of Isaiah to King Hezekiah:
"Behold, the days are coming, when all that is in your house, and that which your fathers have stored up till this day, shall be carried to Babylon. Nothing shall be left, says the Lord." Isaiah 39:6
Under the news of this prophetic word, the Jews who were still trying to serve the Lord needed encouragement, comfort and assurance.
They would need the teaching of these chapters that they might be consoled by the promises of God.